If they were rotted, wouldn't ALL cylinders get water? I also had brand new ones installed when motors were rebuilt in '05. The mating surface of old ones was corroded a little.
Oh, and there is some water in oil. Noticed oil level was about 1 quart over full, still looked good though. But on the bottom of the oil fill caps on valve covers - milkshake!

I had the same problem, only worse. A head, Dart Iron Eagle, cracked in half sideways, less than 10 hours on a 540. When Dart was notified, they said it was an issue with marine engines and gave me two new aluminum Pro1's. Over $5,000 worth of damage and port work I was out of luck on.

I had the same problem, only worse. A head, Dart Iron Eagle, cracked in half sideways, less than 10 hours on a 540. When Dart was notified, they said it was an issue with marine engines and gave me two new aluminum Pro1's. Over $5,000 worth of damage and port work I was out of luck on.

Dart did the same thing for my friend a couple years ago.....

Luckilly his engine just filled up with water and didn't wipe out any other parts...